Example embodiments disclosed herein are related to nonvolatile memory devices, for example, to a flash memory device extracting parameters therefrom.
Nonvolatile memory devices, such as flash memory devices, are electrically erasable and programmable read-only memories (EEPROMs) in which a plurality of memory regions are erased or written with data by one-time operation of programming. A traditional EEPROM is operable such that a single memory region is erasable or programmable at a time. Thus, the flash memory device operates more rapidly and effectively in reading and writing data when systems employing the flash memory device read/write data from/into different memory regions at the same time. Many types of flash memory devices or EEPROMs are usually configured in structure such that insulation films enclosing charge storage elements used for storing data are inevitably worn out after a specific number of operations.
Flash memory devices reserve information on their silicon chips even without a power supply. For example, flash memory devices are able to retain their information without power consumption even in a condition of power interruption to the chips thereof. Additionally, flash memory devices are generally more resistive to physical impacts, thus offering faster accessibility for reading. As a result, the flash memory devices are generally used as storage units in electronic apparatuses powered up by batteries. Flash memory devices may be classified into two types, e.g., NOR and NAND types, in accordance with a logical array pattern of gates used each for storage elements.
A flash memory device is configured to store information in an array of transistors called cells, each of the cells containing at least 1-bit data. A multi-level cell (MLC) flash memory device is able to store more than 1 bit by varying an amount of charge accumulated in a floating gate of the transistors.